"Seamen tell me that there are great curling seas which will swallow up anything;and I can fully understand that no vessel could live in the heavy breqakers to be met with on the Cornish coast; but I have run before curling seas, of certainly from 18 to 20 feet high, off Cromer, and yet nothing of any importance has ever come on board. I have looked behind and seen waves which threatened to curl right over me; but they always run under the ster, the white water rushing along the descks on each side sifficient to drown an open boat, but of no consequence to a decked on.
Again the length of twenty-one feet is of the greatest advantage when running , for the boat only contends with one sea at a time; whereas greater length is sometimes hung on two, and frequently overruns the seas. The wave usually carries The Kate along with it - for this rreason, that the greatest beam is about three feet aft of the mainmast. The sea therefore holds onto that point and sweeps the boat along on its edge (if it is curler) until broken, when the staunch little craft rushes through the white water as smoothly as possible."
EE Middleton - the Cruise of the Kate 1868